It has warned of the possible loss of 350 jobs if the planned sale of the terminal was not approved by the competition watchdog.

Aurizon has previously announced the sale of its intermodal freight business to Linfox for $7.3 million. That deal will include including freight forwarding and pick-up-and-delivery assets, rail wagons, the transfer of customer contracts and employment of the majority of Aurizon's QIB employees, as well as access to terminals.

Aurizon has offloaded its inter-modal freight business in Queensland.

The ACCC claims the acquisition of the terminal by Pacific National would substantially lessen competition by raising the barriers to entry for potential new rail operators.

Aurizon said it did not accept the Federal Court had made an error in giving approval to the sale of the terminal. It said if the ACCC appeal proceeded, the sale would not be settled until the matter is heard and finalised before the full bench of the Federal Court.

ACCC chair Rod Sims said the watchdog remained concerned that if Pacific National was allowed to acquire the terminal, it would have the ability to discriminate against competitors. "There are many subtle ways in which it could disadvantage a competitor in their day-to-day operations," said Mr Sims.

The Acacia Ridge terminal is linked to a standard gauge rail line that was used by both Pacific National and Aurizon, the only providers of intermodal rail freight within Queensland.

Aurizon has said a failure to approve the sale could trigger job losses throughout Brisbane and regional Queensland including positions lost at Mackay, Gladstone, Rockhampton, Emerald and Longreach.